The invention is concerned with a procedure for cutting brick blanks from an extruded strand of green brick material known as clay columns. The invention is also concerned with apparatus for carrying out that procedure.
It is known that individual brick blanks can be cut from a clay column by pushing that column at right angles to the direction the column is moving through a cutting frame employing tightened wires. This is shown in U.S. Pat. Nos. 3,461,196 and 3,602,963.
Such devices are chiefly used in the outer wall industry, where columns are pressed or squeezed very hard, for example, in order to produce certain surface structures or designs on the bricks.
The disadvantage of these devices is the fact that, in cases where a firm pressing is not possible or desirable because of the characteristics of the raw material or because of the construction of the column for example, for the production of hollow bricks, a push-through cutter cannot be used since the pushing element would deform the column or leave strong markings on the head ends of the bricks. Further, these wires can leave ragged and sharp edges on the bricks which can subsequently injure individuals handling the bricks.
Cutting clay columns with a cutting device by means of a cutting frame, supported so that it can rotate, in which cutting wires are located at intervals from each other is also known. The column is conveyed on a transportation device comprised of a number of narrow conveyor belts located close to each other, and the cutting wires sink into holes or spaces defined between the belts after every cut.
The disadvantage of this apparatus, which now, in fact, can divide hard or soft clay columns consists in the fact that a separate belt table or assembly line must be available for each cut length so that changing cutting lengths is a very time-consuming and expensive operation. Another disadvantage of this device is the fact that the clay columns are not completely supported during cutting, so that the lower edges of bricks can be deformed when being cut. Further, the wires can only be cleaned after every cut by a relatively time-and-energy-consuming device, and since the cleaning device has to be moved along the wires while they are held in a stationary position an additional time delay factor is created.
Furthermore, cutters for cutting brick blanks from clay columns using cutting frames with a large number of cutting wires, is also known, with the wires operating through holes or spaces between conveyor belts installed close to each other or in sheet metal supports, or by sinking into them.
These devices also have the disadvantages described above, for example, that individual assembly lines are required for each cut length, and they have to be switched each time the cut length is changed.
In contrast, the basic task of the present invention is to cut brick blanks from clay columns in a simple manner and with great efficiency, by having the clay column lie on a continuously wide conveyor device during cutting with the width being at least as wide as the longest clay column. Accordingly, the conveyors do not have to be switched when the cut length changes.
In contrast with the familiar devices described above, the present invention has significant advantages in that no slide is used for cutting the brick blanks which would otherwise press the column through the wires of the cutting frame. Further, the wires do not sink into holes between conveyor belts located next to each other, so that no assembly lines, tables or other supports have to be switched when changing cutting lengths. Also, the wires can be cleaned by a simple device during cutting.
Accordingly, it is the primary object of the present invention to provide not only a high capacity cutting method and device, but a highly efficient one as well which produces high quality bricks. These and other objects will become apparent from an inspection of the detailed description together with the following schematic diagrams.